Germanium (Ge)-containing layers, such as pure Ge, doped Ge, or essentially non-silicon containing Ge, have attracted attention due to high electron mobility. The high electron mobility of Ge-containing layers may be advantageous at smaller device nodes, such as 15 nm or less. For example, a Ge-containing layer may be used as a channel for a logic device, such as a metal oxide semiconductor field effect transistor (MosFET) or as a component in any device, interconnect structure, or the like where high electron mobility is required. Unfortunately, a pure Ge layer grown on a silicon-containing surface has a high defect concentration due to a lattice mismatch between the silicon-containing layer and a layer of pure Ge. A high concentration of defects in the Ge layer reduces carrier mobility and/or active dopant levels in the Ge layer.
Therefore, the inventors have provided improved methods for depositing Ge-containing layers on substrates.